There are many miniature personal electronic devices available today adapted to be worn on the body and providing a variety of features and functions to the wearer. Examples of such devices include watches, calculators, miniature broadcast receivers, and even miniaturized personal body function monitoring devices. These miniature personal electronic devices are available in a variety of forms, such as wristworn devices, as watches, and devices which are clipped or hung on the body, as pendants or broaches. Many of these devices include receiver functions requiring an antenna to be incorporated in the design of the device, thereby providing a miniature personal communications device. Various methods of incorporating the antenna into these prior art miniature personal communications devices have been proposed. The antenna has variously been located in the wristband of the device, externally connected to the case of the device, or included within the case of the device. In each instance, tuning of the prior art device antennas has been achieved by tuning elements located in the case of the device which can only be accessed by opening the case of the device.
In addition to having to enter the case for access to modify the antenna tuning elements, prior art devices also require access into the case to access the test or metering point providing the indication that the antenna is being tuned. Without access to the metering point, tuning of the antenna and subsequently the receiver itself, is impossible.
Most antennas, including those provided in prior art devices are generally detuned, when they are brought into close proximity to the body. Thus, prior art tuning methods which are internally performed and require access into the device case, do not optimize the "on the body" antenna sensitivity. Optimum antenna performance can only be achieved when the device is tuned in situ, on the person who is to wear the device.
Several problems are specifically encountered when incorporating the antenna into the means adapting the device to be worn on the body, such as a wristband. First, the size of the person's wrist causes large variations in antenna sensitivity compared with that achieved during initial tuning. Also, most wristbands, because of the flexing, twisting and general abuse they receive during normal wear and through daily removal and replacement, result in periodic replacement of the wristband. The requirement to enter the case for wristband replacement and retuning makes this task both time consumming and expensive. Also, variations in the manufacturing process required to make an antenna suitably located in a wristband results in wider variations of electrical characteristics than would ordinarily be encountered in conventional internally located antennas. These and other problems associated with the prior art designs are overcome by the use of the invention described in detail herein.